// 实现 a === a + 1
global.a = 10
let val = 10
Object.defineProperty(global, 'a', {
  get: function () {
    return --val
  }
})
console.log(a === a + 1)

let kidding = 10
const proxy = new Proxy({ }, {
  get: function (target, key) {
    console.log(target)
    return --kidding
  }
})
console.log(proxy.b === proxy.b + 1)
